|Color & Icon|Name|Name|Mark|First section opened|Last ex- tension|Length|Stations|
|---|---|---|---|---|---|---|---|
|yellow|Line 1|Higashiyama Line|H|1957|1982|20.6 km (12.8 mi)|22|
|purple|Line 2|Meijō Line|M|1965|1971|8.9 km (5.5 mi)|12|
|purple|Line 4|Meijō Line|M|1974|2004|17.5 km (10.9 mi)|17|
|purple & white|Line 2|Meikō Line|E|1971|-|6.0 km (3.7 mi)|7|
|blue|Via trackage rights|Meitetsu Inuyama Line|-|1993|-|21.4 km (13.3 mi)|13|
|blue|Line 3|Tsurumai Line|T|1977|1993|20.4 km (12.7 mi)|20|
|blue|Via trackage rights|Meitetsu Toyota Line|-|1979|-|15.2 km (9.4 mi)|8|
|blue|Via trackage rights|Meitetsu Mikawa Line|-|N/A|-|1.4 km (0.87 mi)|2|
|red|Line 6|Sakura-dōri Line|S|1989|2011|19.1 km (11.9 mi)|21|
|pink|Via trackage rights|Meitetsu Komaki Line|-|2003|-|18.3 km (11.4 mi)|13|
|pink|Via trackage rights|Meitetsu Komaki Line|-|2003|-|2.3 km (1.4 mi)|2|
|pink|Line 7|Kamiiida Line|K|2003|-|0.8 km (0.50 mi)|2|

Question: how many lines exist in total?
Answer: 7